Positive Psychological Intervention Effects on Depression: Positive Emotion Does Not Mediate Intervention Impact in a Sample with Elevated Depressive Symptoms

Abstract

Positive psychological interventions (PPIs), programs that specifically target positive emotions, cognitions, and behaviors, have been shown to reduce depression and improve other aspects of psychological well-being. However, potential pathways linking PPIs to better outcomes have been under-explored. In this paper, we report the results of a randomized trial of a self-guided online delivered PPI called MARIGOLD (Mobile Affect Regulation Intervention with the Goal of Lowering Depression). Participants with elevated depression were randomized to receive MARIGOLD (n = 539) or an emotion reporting control condition (n = 63). In addition to testing direct effects of the intervention on depressive symptoms, we explored whether positive or negative emotion—operationalized as past day, past week, reactivity, or flexibility—mediated the intervention impact on depression. Results demonstrated that participants in the MARIGOLD condition had reduced depressive symptoms compared to controls and, although the effect did not reach statistical significance, reductions in past day negative emotion appeared to mediate this effect. Contrary to hypotheses, the intervention did not increase positive emotion compared to the control condition. Discussion focuses on the need for future studies to continue investigating the mechanisms of action for PPIs with emphasis on theoretically-based measurement and operationalization of emotion and other potential mediators to maximize the ultimate impact of PPIs on psychological well-being. Clinical Trials registration #NCT02861755.